Troubleshooting

First, please check that you're running the latest version, log out of macOS and back in again and see if the problem remains.
Check that you don't have other copies or versions of QuickLook Video lying around which might confuse QuickLook and/or Spotlight. The QuickLook Video app offers to delete any version 1.x plugins that it finds, but you can delete them manually by copying the following, pasting in the Terminal app, and pressing Enter:
```
rm -rf ~/Library/Application\ Support/QLVideo ~/Library/QuickLook/Video.qlgenerator ~/Library/Spotlight/Video.mdimporter; sudo rm -rf /Library/Application\ Support/QLVideo /Library/QuickLook/Video.qlgenerator /Library/Spotlight/Video.mdimporter
```

Finder doesn't show thumbnails for "non-native" video files

Under System Settings → Privacy & Security (scroll to the bottom) → Extensions → Quick Look ensure that QuickLook Video thumbnails is checked. Try unchecking and checking this setting.
Run the QuickLook Video app and press Refresh. This tells QuickLook to clear its thumbnail cache and then restarts Finder to make it refresh its thumbnail cache.

Spotlight can be slow to notice new indexers. You can check whether Spotlight has found the plugin supplied by this app by typing mdimport -L in the Terminal and checking whether "/Applications/QuickLook Video.app/Contents/Library/Spotlight/Video.mdimporter" is listed. If it isn't listed, then check whether you have any other copies of the QuickLook Video app lying around (Spotlight doesn't like multiple copies). You may have to log out and back in again.
If you see a message in the QuickLook Video app about high CPU and disk usage then Spotlight has found the plugin and the app has asked it to re-index video files. Re-indexing happens in the background so it may take a few minutes before you can see the metadata in Finder.
Once Spotlight has found the plugin:
- You can force it to re-index video files by copying the following, pasting in the Terminal app, and pressing Enter:
```
mdimport -r "/Applications/QuickLook Video.app/Contents/Library/Spotlight/Video.mdimporter"
```
- Alternatively, you can force Spotlight to re-index all the files in a folder with mdimport -i /path/to/folder

From the QuickLook Video app's Help menu, choose Report an Issue.
Drop any problematic file and press Send.
Give the new Issue a title, describe the problem and press Submit new issue.